In 3D object printing, objects are built one layer at a time. The one or more printheads ejecting the drops are moved over the object multiple times. The number of passes required to produce an object can result in extremely long times for production of a typical object. Some objects are so large that several days may be required to form the object. In addition to the materials ejected by a 3D printing system that form the structure of an object, some printing systems also include pigmented materials of overlaying images on the surface of a produced part. In these systems, the object structure is typically formed with clear and white build materials and colored materials, such as the colors commonly used in two-dimensional printing, namely, cyan, magenta, yellow and black (C, M, Y, and K), are used to form the images. As used in this document, “colored material” or “pigmented material” refers to materials having a hue in the light spectrum range from red to violet and black. Each layer is made of only one type of the material, that is, either build material or pigmented material. One way to reduce the time required to form an object is to print multiple layers in a single pass. In order to achieve this goal, the number of ejectors assigned to each material must also be increased. Of course, this increase in the number of ejectors also increases the cost of the system since it is a hardware expense. Therefore, a direct relationship between speed and cost exists in the 3D object printing systems.
Issues also arise with the printing of images with pigmented materials because printing color on the surface of 3D objects is not the same as applying paint to a surface. Paint has colorant concentrations that are far greater than those that can be incorporated into materials that can be ejected by printheads. In printing colors, white material may be used as a base for an image and then the image is formed with various color combinations. Thick layers of colors, however, cannot form high resolution images. Additionally, many 3D object printing systems include a leveling device that is used from time to time in the manufacturing process to remove some material to level the surface. This leveling is required because the addition of other layers on top of an unlevel surface can disrupt the configuration of the object being manufactured. The amount of material removed can also produce unacceptable variations in color. A 3D object printing surface that reduces the manufacturing time and that reliably reproduces colors at the surface of the objects would be beneficial.